1 package com.twister; 2 3 import java.util.ArrayList; 4 import java.util.Collections; 5 6 public class Points implements Comparable<Points>{ 7 int xCoordinate; 8 /* 9 * 1. Returns 0 if both points have same xCoordinate (say 3 & 3) - returns 3-3=0 10 * 2. Returns +ve if first point is on the 11 * right hand side of the second point (say 5, -3) - returns 5 - (-3) = 8 12 * 3. Returns -ve if first point is on the 13 * left hand side of the second point (say -5, 3) - returns (-5) - (3) = -8 14 */ 15 public int compareTo(Points p) { 16 return xCoordinate - p.xCoordinate; 17 }; 18 19 public static void main(String[] args) { 20 ArrayList<Points> arrPoints = new ArrayList<Points>(); 21 /* Add lots of points to the array list */ 22 Collections.sort(arrPoints); 23 /*Print the sorted collection */ 24 } 25 }